Yieldable propeller



Jam 20, 1931. s, LILLY 1,789,874

' YIELDABLE PROPELLER Filed 001;. 15,, 1928 Snow doc Scott HLMIH.

In 19. %rdinarily the blades will be maintained in mm; Jan. 20, 1931PATENT OFFICE scorer 1:. unit, or romno, omaassronoa, 3r unsmaassrenmnnrs, r0 sr. nears rum com-m, or new roux, N. 2., acoaromrron ornew YORK YIELDABLE PROPELLEB Application filed October 15, 1828. SerialNo. 812,496.

This invention relates to a yieldable propeller and has for its objectto provide a problades which automatically adjust themse s glroximatelyeven pressure u on the material vertical section,

scharged, regardless of t e rate of discharge. g

The invention will be described as aBphed to a device similar to thatdisclosed in atent No. 1,658,734, issued to Lewis D. Nelson February 7,1928, for feeding material into valve bags, and is particularly adaptedfor feeding granular or pulverulent material.

In the accompanying drawings forming a part of this specification,Figure 1 shows a on the line 11 of Figure 2, throu h a propellerembodying the invention, wit a portion of a casing suflicient toindicate the relation of the propeller to the casing; Fi re 2 is a planview of the'parts shown in i 1; Fig. 3 is a fra mentary section on thelme 3--3 of Fig. 1; ig. 4 is a detail view showing a portion of apropeller blade.

In the construction shown, there is a casing 10 which may be .ofsubstantially cylindrical formation, having a bottom 11 and a dischargespout 12 at one side thereof adjacent the bottom. Immediately above thebottom there is a disk 13 having a conical boss 14 around its center andmounted upon a vertical shaft 15, which may be driven in any desiredmanner. Attached to the u per' surface of disk 13 there is a series oflades 16. The blades are shown mounted in ooves 17 formed in the upperportion of dis 13.

In the construction shown, the bottom 18 of the groove is formed so thatthere is a substantia 1y portion of boss 14 to the outer end of oove 17.The upper side of the groove 17 1s narrowed towards the outer edge ofthe disk so as to leave overhanging In S 19. A flange 20 is attached tothe lower e go of each blade 16 and is adapted to fit into. a groove 17the "flange being notched at 21 to receive lugs 19, and the shoulder 22at the end of the notch 21 being adapted to rest against the inner endof the radii of the disk which would I through said top, and, therefore,

continuous curve from the upper.

position by centrifugal force and the friction of the material thereon,which both operate to crowd the blades outward to the limit allowed byshoulders 22 and lugs 19; but, if desired, the flange 20 may be providedwith a hole 23 registering, when the blade is in position, with a hole24 in the bottom of groove 17, and the blade may be secured in positionby a screw 25 passing through the holes. As will be seen most clearlyfrom Fig. 3, the blade is normally curved so that the top 26 is advancedin the direction towards which the propeller revolves, as indicated byarrow 27. The blades aremade ofspring metal so that the will yield underpressure.

Ili will be readily understood that the mate- -rial in casing 10 fallsdown by gravity into the path of the revolving blades. In theconstruction shown, the bottom of the blade is arranged radially of disk13. The top 26 of the blade is parallel with the bottom of the blade,but since it is normally positioned in advance of the bottom, asindicated in Figs. 2 and 3, the top of the blade is at an angle to passhas a tendency to crowd material outward away from the center of thedisk. At the same time, the curvature of the blade acts to crowdmaterial downward and prevent its return upward into the casing. Theresult is that material caught in front of a blade is forced downwardand outward until it escapes in the direction of arrow 28 through outlet12, as long as the blade maintains its normal position.

When the flow of material from the outlet is obstructed'by the closureof gate 29, or for any other reason, the resistance encountered theblades is increased so that the top of e blade is pressed backwardnearer to the radial plane passing throu hthe bottom of the blade. Itwill be readi y seen that when the top of the blade far that the bladeisvertical, the material is no longerpressed downward by the curved.

is pressed backwards so material, as discussed above,

twisting action of the free end of upper the gate is closed, there maybe a continued pressure which will bend the top of the blade evenslightly back to the bottom thereof. In

this case, the reverse condition from that first described results,

press material inward and upward sufiicientto counterbalance the excesscentrifugal orce.

It will be readily seen from the above that yieldable blades mounted inthe described manner result in a continuous pressure on the materialduring the revolution of the propeller, which pressure is automaticallymaintained within a comparatively narrow range by the straightening ofthe blades when resistance is encountered, and their return to normalposition when, resistance is lessened. In this way the feeding forceexerted upon the material remains within comparatively narrow limitsregardless of the speed of discharge of material.

The number of blades may be varied as desired. In the constructionshown, disk 13 is grooved for six blades, with-the blades such distanceapart that at least one of them will.

be constantly forcing material towards the outlet passage.

For various reasons it is desirable to have the discharge of atpackage-filling device as nearly constant an uniform as practicable.The construction of the blades is such that they tend to exert a uniformpressure on the and the ample ment of a considerable number of bladesten to make the discharge more uniform during each revolution of thepropeller.

In the construction shown, the blades are illustrated as bein ofsubstantially as large size as can be fitte on the disk outside of t ecentral cone. As will be seen from Fig. 1, the inner end of the upperedge 26 of the blade projects to the rear of the cone, as viewed in thatfigure, butwhen the blade is straightened up the upward edge is raisedsufiiciently to escape being obstructed in its movement by the centralcone.

It will be readily understood that a greater or less degree of curvaturethan that disclosed in the drawin as well as a variation in the numberof bla es utilized, may be made without departing from the principles ofthe invention. Furthermore, if desired, the" shape of the blade may beotherwise varied.

At the right of Figures shown a blade 30 which has a top portion 31extendin approximately as farradially of the prope er as blades 16 butbeing comparatively narrow vertically and connected to the bottom flangeb a shank 32. In this case the blade is curv zontal plane as well as inthe vertical plane so that when it meets with resistance the tion 31will tend to straighten shan 2 vertically and horizontally.

so that the blade tends to it will be understood that -a lateraldischarge openin land 2 there is normally in the horirthsaid outer endAt the lower left portion of Fi re 2 there is shown a blade 33 similarto bla e 16 exce t that the upper portion is no longer than t e bottomthereof.

It will be readily understood that various other modifications may bemade in the shape of the blades, as well as in their number,

within the scope of the appended claims.

What I claim is: 1. In apparatus of the character described,

an approximately cylindrical casing havin rotatably, substantiallyconcentric with the and are moved towards a vertical position byresistance of material.

2. In apparatus of the character described,

an a proximately cylindrical casin having a disc arge outlet t rough thesi e thereof adjacent one end and a propeller mounted rotatably,substantially concentric with the casing, and in register withsaidopening, the propeller being provided with spring blades normall curvedin a direction to force the materia towards the end of the casing andoutward therefrom but so that pressure thereon will tend to straightenthe blades towards a radial position.

described,

3. In apparatus of the character tin-approximately cylindrical casinhaving a rough-the si e thereof and a propeller mounted rotatably,substantially concentric with the discharge outlet t adjacent one endcasing, and in register with said opening, the

pro ller being provided with spring blades,

'sai blades bein mounted on their edges towards the end 0 the casing andhaving said ed es extend substantially radial of the proler and theblades normally curving away om said edges and in the direction ofrotation of the propeller.

4. In apparatus of a casing having a substantially .cylmdrica portionwith a substantially vertical axis and bottom thereof, and a prope er inthe bottom of the casing substantially concentric therewith andcomp'risin a disk in the bottom of the casing and bla I upon the upperside of the disk, said blades being substantially in registerwith'saidd1 scharge opening, having one edge held rigid radially of the disk andbeing curved forward to normaly tend to press and be moved towards fromsaid edge so as material downward I a vertical position b resistance ofmaterial.

5. In a paratus o the character described, a rotatab e propellerprovided with a blade mounted ad acentits radially outer end and havinga resilient portion extending from towards the axis of the prothecharacter described I es of resilient material 7 adjacent the l'peller,but normally in advance of said outer end in the direction ofthe rotation of the a lateral discharge opening adjacent the botv wardand there portion of said grooves and bla tom thereof, and a propellerin the bottom of the casing, substantially concentric therewith, andcomprising a disk in thebottom of the casing and resilient blades uponthe upper side of the disk, said blades being substantially' in registerwith said discharge opening and having their bottoms extendsubstantially radial of the propeller, the curvature of the blades beingsuch that the major portion of each blade is normally ahead of thebottoms thereof in the direction of rotation of the propeller.

1 7. In apparatus of the character described, a casing having asubstantially cylindrical portion with a substantially vertical axis'and a lateral discharge opening adjacent the bottom thereof, and apropeller in the bottom of the casing, substantiallyconcentrictherewith, and comprising a disk in the bottom of the casing,the disk havin g a hub portion rising from its upper side, the outerside of the hub portion being curved-downward" and outward and therebeing grooves inthe upper surface of the disk, the bottoms of saidgrooves being substantially of a continuation of the curve of the outersurface of said hub and there being stop lugs in the upper outer portionof said grooves, and blades having flanges on their lower edges adaptedto enter said ooves and abut against said lugs to position the blades.

' 8. In apparatus of the character .described a casing having asubstantially cylindrical portion with a substantially vertical axis anda lateral discharge opening adjacent the bottom thereof, and a propellerin the bottom of the casing, substantially concentric therei with, andcomprising a disk in the bottom of -the casing, the disk havin a hubportion rising) from its upper side, t e outer side of the hu portionbemglcurved downward and outeing grooves in the upper surface of a thedisks, the bottoms" of said grooves being substantially a continuationof the curve of the outer surface of said hub. and there being stop lugsin the u per outer dies having mounted along a line substantiall radialof the propeller and being norma ly curved away from said line ofsupport forwardly in .forward position with respect to the rotation ofthe propeller, but movable towards its rearward position by pressure ofmaterial being fed.

11. In apparatus of the character described, a substantially cylindricalcasing having a radial discharge opening, and a propeller rotatableabout an axis extending longitudinally of the casing, said propellerbeing in the radial plane of said 0 ening and comprising a bladeextending su stantially radially but with its inner portion normally inadvance of its" outer portion, said blade being resiliently held inposition and the inner portion being constructed to yield under pressureof propelled material a greater distance angularly of the propeller thanthe outer portion yields under like resistance.

In testimony whereof I have hereunto signed my name to this scification.

' S6 TT H. LILLY.

flanges on their lower edges adapted to enter said grooves and abutagainst said lugs to position the blades, said blades being made ofspring material and the upper sides thereof bemg normally in advance ofthe side connected to said flanges. A

9. In apparatus of the character described, a casing, and a propeller inthe casing having a blade of spring material, said blade being

